This invention relates to a gooseneck trailer adapted to be coupled to a tractor and particularly to a trailer in which the gooseneck is supported at the front end of the trailer for swinging movement between a closed towing position and an open loading position.
A low-bed trailer is used to haul very heavy loads such as road equipment and heavy machinery, the load deck height being as close to the ground as possible for ease in loading and to provide a low center of gravity for the loaded trailer. When larger diameter tires are required to carry very heavy loads, a trailer of the drop deck type is used in order to minimize the deck height.
Due to the difficulty and impracticality of trying to load very heavy loads over the rear or the side of a low-bed trailer, of either the level deck or drop deck type, low-bed trailers have been designed in which the gooseneck is removable. The gooseneck includes a hydraulic system or a winch by which the forward edge of the load deck is lowered to the ground, after which the gooseneck is disconnected from the load deck and moved completely away therefrom. The load can then be loaded over the forward portion of the load deck, which acts as a loading ramp. The hydraulic system on the gooseneck may include a gasoline engine and a driven hydraulic pump, or oil under pressure is obtained from the tractor. Alternatively, a winch mounted on the tractor lowers the trailer to the ground and removes the gooseneck.
In an effort to avoid the expense and maintenance required by special gasoline engines, winches, hydraulic pumps and cylinders, etc., a pivotably mounted gooseneck was proposed in the Polich U.S. Pat. No. 2,878,033. Here the gooseneck is pivotally connected to the front of the trailer deck at one side thereof, so that the gooseneck may swing away from the front of the deck for front loading or unloading. This proposal has never been commercialized, however, because it is impossible for one man to swing the gooseneck between the towing position and the open or loading position. This is because the gooseneck is the entire support for the front of the trailer, which may have a capacity of 60 tons, for example, and it is the gooseneck that connects the tractor to the trailer. Accordingly, the structural requirements for the gooseneck are such that it is too heavy for one person to swing.
In an effort to overcome this difficulty, the hinged gooseneck according to the Felburn U.S. Pat. No. 3,151,884 is split into two sections, which may be swung away toward opposite sides. When the trailer is to be towed, the two sections are bolted together. This version has not met with success, however, because the splitting of the gooseneck seriously compromises its strength.
These and other disadvantages of the prior art gooseneck trailers are overcome by the present invention.